1. Field of the Invention
This invention relates to a plasticizing assembly for use in an injecting unit of an injection molding machine, comprising a heatable plasticizing cylinder, a rotatable and axially displaceable plasticizing screw that is disposed in said plasticizing cylinder, and a reinforcing skeleton, which partly encloses the plasticizing cylinder and comprises at least one skeleton element which constitutes a track that is spaced from the plasticizing cylinder and serves to cooperate with a stationary roller so as to guide the plasticizing cylinder during the cyclic axial reciprocating motion of the injecting unit during the injection molding sequence.
2. Description of the Prior Art
In a plasticizing assembly of that kind, which is known from U.S. patent application Ser. No. 07/079,109 now abandoned, the reinforcing skeleton elements which constitute tracks for supporting for the plasticizing cylinder when it is at rest and for gripping the plasticizing cylinder when it is to be carried away. The plasticizing cylinder is surrounded in part by a channel-shaped guard, which is connected to the plasticizing cylinder by U-shaped clamping members and carrying bars. To establish the connection, the free end portions of the horizontal bars extend through the vertical legs of the channel-shaped guard, which along its lower bend lines constitutes horizontal and vertical tracks for the stationary rollers. In that respect the guard is a permanent component of the reinforcing skeleton and cannot readily be removed without the assistance of skilled employees of the manufacturer. When a repair or replacement is required, those functional elements of the plasticizing assembly which are disposed within the guard, particularly the heating elements, will be accessible only with difficulty.
From German Patent Publication 29 07 557 and the corresponding U.S. Pat. No. 4,278,354 it is also known to support the plasticizing cylinder of a comparable plasticizing assembly by means of skids on the track rods of the injecting unit.
It is also known from U.S. Pat. No. 3,068,521 that a plasticizing cylinder which is fixedly mounted in the central bore of the receiving body can be protected by an enclosing sheet metal shell.